1. Field of the Invention
This invention relates to seatbelt systems and more particularly to seatbelt systems which make it possible to automatically fasten the passenger-restraining belt around the passenger after the passenger has seated himself in the vehicle.
2. Prior Art
Seatbelt systems restrain passengers during vehicular emergencies such as collision, et., and therefore, make it possible for a passenger to avoid colliding with dangerous objects within the vehicle. As a result, passenger safety is conspicuously improved. However, the percentage of passengers who wear seatbelts is extremely low because of the difficulty in fastening the belt, etc. As a result, various types of seatbelt systems have been proposed which makes it possible to automatically fasten the belt around the passenger after the passenger has seated himself in the vehicle.
Among such seatbelt systems, a common design is one in which the outer end of the passenger restraining belt is anchored to a runner piece and the belt is moved by moving the runner piece along a guide rail fastened to the vehicle body. In this way, the belt is caused to approach or move away from the passenger seat so that the belt is automatically fastened around or removed from the passenger. During a vehicular emergency, however, a large belt tension is transmitted to the belt guide which supports the runner piece. Accordingly, it is necessary that the guide rail be strong. However, it is also necessary to provide space in the guide rail for the installation of various transmission parts which transmit the driving force of a motor, etc. to the runner piece. As a result, the size or the guide rail has been conspicuously increased. This decreases the amount of passenger space available in the vehicle and increases the danger that the passenger collide with a part of the system projecting into the passenger compartment.